Method and apparatus for blending ceramic fibers with carrier fibers



Dec. 12, 1961 J w WEBER 3,012,289

METHOD AND APPARATIJS FOR BLENDING CERAMIC FIBERS WITH CARRIER FIBERSFiled May 13, 1957 2 Sheets-Sheet l INVENTOR. v John W Weber H/ ATTORNEYDec. 12, 1961 J. w. WEBER METHOD AND APPARATUS FOR BLENDING CERAMICFIBERS WITH CARRIER FIBERS 2 Sheets-Sheet 2 Filed May 15, 1957 IN VENTOR. John W. Weber H/ ATTORNEY United States Patent 3,012,289 METHOD ANDAPPARATUS FOR BLENDHNG CERAMIC FIBERS WITH CARRIER FIBERS John W. Weber,Norristown, Pa., assignor to The Carborundum Company, Niagara Falls,N.Y., a corporation of Delaware Filed May 13, 1957, Ser. No. 658,582 8Claims. (Cl. 19146) This invention relates to a method and apparatus forblending ceramic fibers with cariier fibers for forming therefrom a webfrom which roving and then yarn is produced. From the ceramic yarn awoven fabric of ceramic fibers can be easily made. This invention isparticularly adapted for producing a web of blended ceramic and carrierfibers which comprises about 25% carrier fibers.

Ceramic fibers are usually brittle and delicate and generally a mass ofas-produced ceramic fibers has a content of shot which must be separatedfrom the fibers before processing them in the production of ceramicfiber yarn. The shot in the mass of as-produced ceramic fibers is smallbeads, pellets and particles of ceramic material which result from themanufacture of the fibers. The brittle and delicate characteristics ofceramic fibers require that a carrier fiber be used along with theceramic fibers in the manufacture of ceramic fiber yarn. Otherwise,during carding and forming a web from which the roving and then the yarnis made, the ceramic fibers break up into small pieces and very shortlengths which cannot be converted into the web. The carrier fibersupports the brittle and delicate ceramic fibers and permits carding theceramic fibers without subjecting a large proportion thereof to damageand to breaking up into unusable short lengths and small pieces. Toprovide a maximum support for the delicate ceramic fibers in themanufacture of ceramic yarn, it is desirable that the carrier fiber beintimately blended with the ceramic fiber. However, because of thebrittle and delicate character of the ceramic fibers, it is essentialthat they receive a careful and a minimum handling and working wheneffecting a blend with the carrier fibers. Usually, the carrier fibercontent in ceramic fiber yarn is about 525% and seldom is less than 5%,but may amount to as much as 40%.

Since many orders for fabrics made from ceramic fiber yarn specify thatthe fabric be resistant to high temperatures and be fire-resistant, itis essential that the carrier fiber content of the ceramic fiber yarn beas low as possible while still being able to support the ceramic fibersuificiently for the production of the yarn. For production of aluminumsilicate yarn, I have found that the carrier fiber content in the yarnpreferably should range between about 5-25% and that a 10% carrier fibercontent produces a good ceramic fiber yarn. Heretofore, aluminumsilicate yarn has been produced only by using 40% carrier fiber in theyarn which amount of carrier fiber is too high to meet the hightemperature and fire-resistant specifications.

Some of the ceramic fibers to which my invention relates are aluminumsilicates, sodium-calcium silicates, calcium aluminates, calciumsilicates, sodium silicates, and glass. I

Some of the carrier fibers which may be used in my invention are acrylicfibers, rayon, cotton, wool, asbestos, glass, polytetrafiuoroethylenefibers, polyamide fibers and polyester fibers.

My invention effects an intimate blend of ceramic and carrier fiberswherein the ceramic fibers are carefully handled and processed so thatthere is a minimum breakup into unusable short lengths and pieces. Theresulting blend of ceramic and carrier fibers produced from practicingmy invention can be utilized to make good strong ceramic fiber yarn andfabricated textiles that meet high temperature and fire-resistantspecifications. Specifically, my invention comprises a method ofblending ceramic fibers and carrier fibers by carding the carrier fibersto form a web of carrier fibers. Next, a mass of ceramic fibers isopened to make a plurality of small tufts of the ceramic fibers and thenthese small tufts are deposited onto the web of the carrier fibers sothat there is a plurality of small tufts distributed upon said web ofcarrier fibers. Then the web of carrier fibers and the small tufts ofceramic fibers are carded to form a Web of blended carrier and ceramicfibers.

My invention is especially suitable for blending aluminum silicatefibers with carrier fibers such as rayon and cotton. Generally, thealuminum silicate fibers range in size from about 2-20 microns.

In the accompanying drawings, I have shown one embodiment of myapparatus which can be used in practicing my invention in which:

FIGURE 1 is a schematic side view of a carding machine for producing theweb of carrier fibers and of an opening machine for making the smalltufts of ceramic FIGURE 2 is a schematic side view of an enlargedportion of FIGURE 1 including a revolved section of a segment of theperiphery of the dofier to show the position of the cutter band thereon;

FIGURE 3 is a section view along the line III-III of FIGURE 2;

FIGURE 4 is a schematic side view of a carding machine which forms theWeb of blended ceramic and carrier fibers; and

FIGURE 5 is a schematic side view of a train of conveyors for carryingthe web of carrier fibers with the small tufts of ceramic fibersdistributed thereupon from the carding line and opening machine ofFIGURE 1 to the carding line of FIGURE 4.

As shown in FIGURES 1 and 4, my apparatus for blending ceramic fiberswith carrier fibers comprises a first carding line 1 which forms acontinuous web of carrier fibers from a mass thereof, an opening machine2 which produces the small tufts of ceramic fibers from a mass ofas-produced ceramic fibers, and a second carding line 3 which forms aweb of blended carrier and ceramic fibers. The delivery end of theopening machine is located adjacent to the delivery end of the firstcarding line so that the opening machine deposits 21 plurality of thesmall tufts of ceramic fibers across and along the web of carrier fibersas the web leaves the first carding line. The train 4 of conveyors shownin FIGURE 5 receives the Web of carrier fibers with the small tufts ofceramic fibers distributed thereupon and carries the web and small tuftsdistributed thereupon to the second carding machine.

The web of carrier fibers preferably comprises randomly oriented fiberswith a substantial or a major portion of the fibers arrangedlongitudinally of the Web and with the balance of the fibers arrangedlaterally and diagonally of the web to impart strength thereto.

A small tuft of the ceramic fibers produced by the opening machinecomprises a plurality of loosely associated fibers which have been tornofi of a mass of as-produced fibers, which have been subjected to asmall amount of combing relative to the amount of combing received on acarding line, and which have been partially separated from one anotherto approach individualization and from which the shot has beenseparated. I have found that tufts which weigh from about l1 /2 to about4 /26 grains are satisfactory for the production of a good Web ofblended ceramic and carrier fibers.

The web of blended carrier and ceramic fibers produced by the secondcarding line is similar to the web of carrier fibers with a substantialor a major portion of the blended fibers being disposed longitudinallyof the web and with the balance of the blended fibers being arrangedlaterally and diagonally of the web to impart strength thereto.

As shown in FIGURE 1, the first carding line 1 has a conventionalautomatic weighing self feed 5 comprising a feed apron 6 which deliversa mass 7 of carrier fibers to a spike apron 8 having a plurality ofspikes arranged in rows across the width of the apron with the spikes inone row being staggered relative to the spikes in the next succeedingrow. As shown, the spike apron is inclined vertically so that itdelivers the carrier fiber to a conveyor apron 9 located beneath theupper end of the spike apron. The spikes on the spike apron tear offtufts it} of carrier fibers from the mass as the spike apron travels inthe direction of arrow 11 and in engagement with a portion of the mass.The spike apron carries the tufts to the top of the automatic weighingself feed where they are removed from the spikes and drop down into theweighing pan for discharge 'onto the conveyor apron 9.

This conveyor apron delivers the tufts to a set of feed rolls 12 which,in turn, transfers the tufts onto a lickerin roll 13. Each of the feedrolls and the lickerin roll has card cloth or wire secured to itsperiphery and extending substantially across its length. The card clothor wire, like the other card cloths or wires referred to hereinafter,has a plurality of teeth arranged thereon with the teeth being adaptedto tear down and break down tufts of fibers into smaller tufts or clumpsbefore passing the broken down and torn down tufts to a succeedingcomponent of the carding line. On a carding line such as lines 1 and 3,the card cloth or Wire on the various elements of the line hasprogressively smaller and finer teeth extending from the feed rolls tothe carder with its main cylinder, worker and stripper rolls to bedescribed hereinafter.

A breast 14 receivesthe tufts from the lickerin roll and performs afurther break down and a combing of the tufts. This breast comprises amain cylinder 15 and two worker rolls 16 and a stripper roll 17interposed between and nearly in contact with the two worker rolls. TheWorker rolls and the stripper roll are nearly in contact with theperiphery of the main cylinder. The main cylinder and each of the workerrolls and the stripper roll have card cloth or wire whereby each combsand Works the tufts to break them down into smaller masses and toapproach individualization of the fibers preparatory to forma ing a web.The worker rolls rotate relative to the direction of rotation of themain cylinder so that they remove some of the tufts therefrom and thestripper roll rotates relative to the direction of rotation of bothworker rolls and of the main cylinder so that it removes the fibers fromboth worker rolls and returns them to the main cylinder. The maincylinder has a surface speed greater than the surface speeds of theworker rolls and the stripper roll and the stripper roll has a highersurface speed than the worker rolls. The relative speeds of the maincylinder of the two worker rolls and of. the stripper roll incombination with the card cloth or wire on the worker and stripper rollsand on the main cylinder effect a combing and working of the tufts toreduce them in size and to bring about an individualization of thefibers.

-A transfer roll 18 with card cloth or wire mounted thereon removes thecarrier fibers from the breast and deposits them on the main cylinder 19of the carder 20. The carder, like the breast, has worker rolls 21 and,in the case of the carder, a stripper roll 22 associated with eachworker roll. The main cylinder, stripper rolls and worker rolls'of thecarder are disposed nearly in contact with each other as shown'in'FIGURE 1 and, like the main cylinder, stripper roll and'the worker rollsof "the breast, have card cloth or wire thereupon with the card cloth orwire of the carder having more rows of teeth per inch and more teeth perrow. The carder operates in the same manner as the breast with the maincylinder having a higher surface speed than the surface speeds of boththe worker rolls and stripper rolls and with the stripper rolls having ahigher surface speed than the surface speed of the worker rolls. Thecarder combs and works the carrier fibers to produce a Web of carrierfibers wherein the worker rolls remove tufts or clumps of fiber from themain cylinder and comb and work these tufts or clumps; then the stripperroll takes the worked clumps and tufts and performs a further combingand working thereof before returning the combed and worked fibers to themain cylinder. The progressive working and combing of the tufts by themain cylinder 1-), the worker rolls 21 and the stripper rolls 22 form acontinuous web 23 of fibers on the main cylinder 19. The worker rollsare so arranged relative to the main cylinder that fibers which havebeen formed into a web escape being picked up by the worker rolls andpass onto a dotfer roll 24.

The doffer roll 24, assisted by a fancy roll 25, interposed between thedoffer roll and the worker roll 21a and disposed nearly in contact withthe main cylinder 1?, removes the individual fibers from the maincylinder. Three cutter bands 26 arranged around the periphery of thedoffer roll, evenly spaced, divide the continuous web 23 into fourwidths 23a, 23b, 23c, and 23d of substantially equal dimension. Both thefancy roll and the doffer roll have card clothing.

The fancy roll digs out and partially frees the individual fibers fromthe main cylinder, thereby permitting the dofier roll to remove thefibers from the main cylinder in web form.

An oscillating doifer comb 27 extracts the four widths of web from thedofier roll and a lattice apron 28 receives the widths and carries themto a position'adpacent the delivery end of the opening machine. There,the small tufts 29 of ceramic fibers are deposited across and along eachwidth of the web just before the web is carried downwardly to rightangle deflector vanes 30 which impart a right angle turn to thedirection of travel of the continuous widths of web (FIGURE 3).

As shown in FIGURE 1, the opening machine 2 has a lattice apron 31 whichconveys a mass 32 of as-produced ceramic fibers to an, automaticweighing self feed 33 equipped with a vertically inclined spike apron34. This spike apron has a plurality of rows of spikes arranged acrossits width with the spikes in one row being staggered relative to thespikes in an adjacent row. The spike apron 34 travels in the directionof arrow 35 and as it passes in engagement with the mass of ceramicfibers, the spikes thereon tear off tufts 36 of fibers and carry them tothe top of the apron. One arrangement of spikes on the apron 34 whichhas produced satisfactory results comprises a spacing of 1%" betweenspikes on a row and a spacing of 1 /4" diagonal dimension between spikeson adjacent rows.

One eccentric rotating comb 37 located about halfway up the apron 34 andpositioned adjacent thereto and a second eccentric rotating comb 38disposed near the top of the apron and positioned adjacent theretoprogressively reduce size of the tufts. The two eccentric rotating combsalso assist in removal of shot from the ceramic fibers. At the bottom ofthe spike apron is a receptacle (not shown) which collects the shotremoved from the mass of ceramic fibers by the spike apron and by thetwo combs.

At the top of the spike apron 34 is a driven stripper roll 39 withprojections arranged across its length and around its periphery forremoving the tufts 36 of ceramic fibers from the spike apron anddropping them into a weighing pan 40 which deposits the tufts into ahopper 41 at regular intervals. When the weighing pan has received acertain number of tufts which equal a predetermined weight, a levermechanism (not shown) opens the bottom of the weighing pan andthe tuftsdrop down into the hopper 41. The hoppe feeds the tufts to a secondfeeder 42 having a vertically inclinde spike apron 43 with its spikesbeing disposed similarly to the spikes of the spike apron 34. On thespike apron 43 there is 1%" between adjacent spikes in a row extendingsubstantially across the width of the apron and 2" diagonal dimensionbetween adjacent spikes in successive rows. From the tufts produced bythe first feeder, the spike apron 43 tears off smaller tufts 29 andcarries these tufts up to its top where they are removed from the spikesof the apron 43 and then delivered onto a conveyor 45. These smallertufts 29 generally are from about one-tenth to one-third the size of thetufts 36 made by the spike apron 34 and weigh between about 1 to 6grains.

Adjacent the top of the spike apron 43 is an eccentric rotating comb 46which is substantially the same as the two eccentric rotating combsassociated with the spike apron of the first feeder. ThiS eccentricrotating comb 46 performs substantially the same function as the twocombs heretofore described.

A second stripper roll 47 extracts the smaller tufts 29 from the spikeapron 43 and transfers them to a downwardly inclined slide 48 havingthree deflector vanes 49 spaced across its lower end. The deflectorvanes divide the smaller tufts into four streams 50. The slide 48discharges these four streams of tufts onto the horizontally disposedconveyor 45 arranged to move the streams to a point above the continuoustraveling widths of web of carrier fibers and there to deposit the tufts29 upon each width of web so that there is a plurality of tuftsextending across and along any given length of a width of web. The smalltufts are delivered onto the widths of web just before the lattice apron28 carries each width over its end 2841 whereupon each width is conveyeddownwardly and given a 90 twist before reaching the right angledeflector vanes 30.

As each width passes underneath a right angle deflector vane, it makes aright angle turn and, in the case of width 23a, it is laid upon ahorizontal conveyor 51. As shown in FIGURES 2 and 3, as the widths movedownwardly to the right angle deflector vanes 30, the small tufts 29fall ofi of that portion of the width onto which they were deposited anddrop down onto a different portion of the same width, which portion hasalready passed underneath a right angle deflector vane 30. Each of theother three widths and the small tufts deposited thereon are subjectedto the same operation with the widths being twisted 90 and passed arounda right angle vane deflector.

The right angle vane deflectors are arranged in tandem so that the fourwidths of web and the small tufts form a stack or pile 52 of successivelayers of a width of web and of small tufts. In other words, width 23abecomes the bottom layer and the small tufts deposited thereon becomethe second layer with width 2312 becoming the third laye and its tuftsthe fourth layer. Correspondingly, width 230 becomes the fifth layer,its tufts the sixth layer; width 23d becomes the seventh layer and itstufts the eighth layer.

The train 4 of conveyors shown in FIGURE carries the pile or stack 52 oflayers of web and of tufts to a feed apron 53 of the second carding line3. The delivery component 54 of this line of conveyors has its upper endpivoted to a portion 55 of a frame which supports the conveyors (all ofthe frame not being shown) and its lower end connected to an endlesschain 56 so that the pile of web and of small tufts is laid transverselyupon the feed apron 53 in continuous lengths as shown in FIG- URE 5.

The second carding line is substantially the same as the first and has aset of feed rolls 57, a breast 58 with a main cylinder 58a, worker rolls59 and stripper rolls 60, a carder 61 with a main cylinder 62, workerrolls 63, stripper rolls 64. a top dofl'er roll 65 and doffer comb 66,and a bottom dofler roll 67 and dotr'e comb 68. Between the top andbottom doifer rolls is a fancy roll 69.

Referring to FIGURE 4, the feed apron 53 of the sec ond carding linedelivers the stack or pile 52 of layers of web and of small tufts ofceramic fibers to a set of feed rolls 57 which transfer the pile to themain cylinder 58a of the breast 58.

This main cylinder and its worker and stripper rolls have card clothextending substantially across its length and wrapped around itsperiphery. As shown in FIG- URE 4, there is a stripper roll for eachworker roll and the main cylinder, worker and stripper rolls operate inthe same manner as the comparable components of the breast 14 of thefirst carding line. This breast 58 combs and works the web of carrierfibers and small tufts of ceramic fibers in the initial blending of theceramic fibers with the carrier fibers and, in addition, converts thesmall tufts 29 of ceramic fibers into smaller clumps or tufts so thatthe carde 61 may more easily form a web of blended ceramic and carrierfibers.

A transfer roll 70 with card cloth secured to its periphery andextending substantially across its length receives the combed and workedweb of carrier fibers and small tufts and clumps of ceramic fibers fromthe breast 58 and transfers them onto the main cylinder 62 of the carder61. The carder 61, like the carder 20 of the first carding line, has aplurality of worker rolls 63 and stripper rolls 64 arrangedsubstantially the same as those of the carder of the first carding line.Specifically, the main cylinder 62 has four worker rolls and fourstripper rolls with a stripper roll associated with each worker roll.The main cylinder and each worker and stripper roll have card clothwhich enables them to comb and work the small tufts of ceramic fibersinto a web of blended carrier and ceramic fibers while avoiding breakingup the ceramic fibers into lengths and pieces too short to card. Also,this carder, like the carder of the first carding line, progressivelyreduces the small tufts and clumps of ceramic fibers so that the tuftsand clumps approach an individualization of fibers and so that theyblend with the carrier fibers and form a web 71 of blended carrier andceramic fibers.

The top doffer roll 65 and the bottom doffer roll 67 remove theindividual fibers from the main cylinde and oscillating dofler combs 66and 68 positioned as shown in FIGURE 4 relative to each doffer rollextract the Web of blended fibers from the dotfer rolls whereupon twoconveyors 72 and 73 pick up the web and carry it to a tape condenser(not shown). The tape condenser forms roving from the web and then windsthe roving onto spools (not shown). The bottom dofl'er roll removes thatportion of the web of blended fibers which escapes the top doffer roll.

Between the top and bottom dofler rolls is the fancy roll 69 which digsout of the main cylinder the web passed by the top dotfer roll, thusenabling the bottom dofi'er roll to easily remove the portion of the webwhich remains on the main cylinder. The card cloth for the fancy roll isgenerally fillet wire.

There is a stripper roll 74 associated With the top doffer roll and astripper roll 75 also associated with the fancy roll. The stripper roll74, associated with the top doffer roll, removes any individual fiberswhich may have been picked up from the top dofier roll and which haveescaped the doffer comb and transfers such individual fibers back ontothe main cylinder. The stripper roll 75, associated with the fancy roll,performs a like function, namely, it transfers from the fancy roll anyindividual fibers which may have been picked up and returns it to themain cylinder.

I have found that the following card wiring for the main cylinder,worker and stripper rolls, fancy roll, and dotfer rolls of the secondcarding line produce a good web of blended and carrier fibers: a cardwire of about 6-12 rows of teeth per inch across the main cylinder andthe worker and stripper rolls of the breast; a card wire of about l2l6rows of teeth per inch across the transfer roll; a card wire of about14-22 rows of teeth per inch across the main cylinder of the cardingmachine; a card wire of about 12-20 rows of teeth per inch across thestripper rolls and worker rolls of the carding machine; a card wire ofabout l220 rows of teeth per inch across the top dofier roll and acrossthe stripper roll associated therewith; a card clothing of about 22-28rows of teeth per inch across the fancy roll; a card wire of about 12-18rows of teeth per inch across the stripper roll associated with thefancy roll; and a card wire of about 18-24 rows of teeth per inch acrossthe bottom dofier roll.

Conventional chain and belt drives operate the first and second cardinglines and the opening machine together with the train of conveyors whichtransport the stack of layers of web and of tufts from the openingmachine and the first carding line to the second carding line. Thesedrives have not been shown or' described since they are well known'andtheir description would only serve to unnecessarily complicate andlengthen this specification.

My invention is the first method which successfully blends aluminumsilicate fibers with carrier fibers to form a web of blended fibers fromwhich commercial roving and then yarn may be produced. Heretofore, thebest efforts in the manufacture of aluminum silicate yarn effectedyields of only -50% of the ceramic fiber used and could only produce theceramic yarn with a carrier fiber content of about 40%. Thus, prior tomy invention, the best efforts produced a yarn which could not meet hightemperature and fire-resistant specifications and which was economicallyunfeasible for commercial production due to the'extremely low yield ofceramic fibers. My invention eifects a web of blended aluminum silicateand carrier fibers from which aluminum silicate roving and yarn can beproduced with yields as high as 70-75% of the total ceramic fibersprocessed being utilized in the final product and with a carrier fibercontent in the final product being as low as about 5%. Hence, myinvention has made possible production of aluminum silicate yarn whichnot only is economically feasible to make but can easily meet hightemperature and fire-resistant specifications. In addition, the lowercarrier fiber content in the v yarn produced by practice of my inventionresults in a I roving and yarn having greater strength at very hightemperatures than yarn heretofore made. a

Practice of my invention now makes available for the first time articlesmade from aluminum silicate yarn which have highly important propertiesand advantages. For example, fire curtains or flame and heat barrierfabrics made from aluminum silicate fibers withstand temperatures in therange of about 2000 F., whereas such curtains and fabrics previouslymade from asbestosclot have been suitable for temperature ranges ofabout 1000* High'temperature gaskets and packings made from aluminumsilicate woven fabrics have the same high temperature advantagesoverthose made from asbestos cloth. In addition, aluminum silicategaskets and packings have greater heat insulating properties than thosemade from glass fibers. a

In the field of high temperature protective clothing, aluminum silicatefabrics have a higher temperature range than those made from asbestoscloth and have a better insulating property than those made from glasscloth.

Braided or wrapped sheathing made from aluminum :silicate yarn hassuperior electrical insulating characteristics than sheathing made froma combination of asbestos and glass fibers and from glass fibers alone.Specifically, wire wrapped with aluminum silicate sheathing has lesscorona and, in addition, the aluminum silicate sheathing withstandshigher temperatures while maintaining its electrical insulating ability.

While a certain embodiment of my invention has been shown and described,it will be understood that it may be otherwise embodied Within the scopeof the appended claims.

1' claim:

1. A meth d of forming an intimate blend of carrier fibers and ofceramic fibers from carrier fibers and from ceramic fibrous materialthat contains a substantial proportion of shot that must be separated toobtain substantially shot-free fibers to permit processing of theceramic fibers, comprising carding said carrier fibers to form a cardedweb of carrier fibers, picking a mass of said ceramic fibrous materialto separate the shot and fibers and to form tufts of ceramic fibers,picking said tufts of ceramic fibers to form smaller tufts of ceramicfibers, depositing said smaller tufts of ceramic fibers onto said cardedweb of carrier fibers so that there is a plurality of said smaller tuftsof ceramic fibers distributed upon said web of carrier fibers, andcarding said already carded web of carrier fibers with said smallertufts of ceramic fibers distributed thereon sufficiently to break upsaid tufts and substantially to individualize the ceramic fibers and tointimately blend the ceramic fibers of the tufts with the carrier fibersof the carded web to form a web of intimately blended carrier andceramic fibers.

2. Apparatus for blending ceramic fibers and carrier fibers comprising afirst carding means for carding a mass of carrier fibers to'produce aweb of carrier fibers, a first picking means for making tufts of ceramicfibers from a mass of ceramic fibers, a second picking means forreducing said tufts from said first picking means to smaller tufts, saidsecond picking means being arranged to receive the tufts from said firstpicking means and being arranged to deliver said smaller tufts onto saidweb of carrier fibers so that said smaller tufts are distributed uponsaid web, and a second carding means for carding said web of carrierfibers and said smaller tufts of ceramic fibers to form a web of blendedcarrier and ceramic fibers.

3. Apparatus for blending ceramic fibers and carrier fibers comprising afirst carding means for carding a mass of carrier fibers to produce acontinuous web of carrier fibers, said first carding means having meansfor dividing said web into at least two widths, a first picking meansfor making tufts of ceramic fibers from a mass of ceramic fibers, asecond picking means for reducing said tufts from said first pickingmeans to smaller tufts, said second pick ing means being arranged toreceive the tufts from said first picking means and being arranged todeposit said smaller tufts onto each of said widths of said web ofcarrier fibers so that the smaller tufts are distributed upon any givenlength of each of said widths,.a second carding means for carding eachof said widths of said web and said smaller tufts of ceramic fibers toproduce a web of blended carrier and ceramic fibers, conveyor meansextending between said first carding means and said second carding meansfor moving said widths of said web from said first carding means to saidsecond carding means,

said second picking means being arranged to deliver said smaller tuftsonto each of said widths as said widths move from said first cardingmeans to said second carding means, said conveyor means having means forplacing one of said widths upon another with a layer of said smallertufts interposed between as said widths travel from said first cardingmeans to said second carding means.

4. in an apparatus for forming an intimate blend of carrier fibers andof ceramic fibers from carrier fibers and from cerarnic fibrous materialthat contains a substantial proportion of shot that must be separated toobtain substantially shot-free fibers to permit processing of theceramic fibers, a first picking means for opening a mass of ceramicfibrous material to separate the shot and the fibers and to make aplurality of small tufts of substantially shot-free fibers, a secondpicking means for reducing said tufts from said first picking means tosmaller tufts, said second picking means being arranged to receivethe'tufts from said first picking means and being arranged to depositsaid smaller tufts onto an already carded web of carrier fibers forblending therewith.

5. A method for forming an intimate blend of carrier fibers and ofceramic fibers comprising carding carrier fibers to form a carded web ofcarrier fibers, picking a mass of ceramic fibers to form tufts ofceramic fibers,

icking said tufts to form ceramic fiber tufts of reduced size and thatweigh from about 1 grain to about 6 grains, delivering thelast-mentioned tufts upon said carded web of carrier fibers to form alayered structure in which there are at least 5% of carrier fibers basedon total fibers, and then carding said layered structure intimately toblend said carrier fibers and ceramic fibers and to form a web from saidintimate blend.

6. A method of forming an intimate blend of ceramic fibers and carrierfibers comprising, carding a mass of carrier fibers to form a uniformcarded web of such fibers, placing said carded web in a horizontalposition, picking a mass of ceramic fibers to form a plurality of smallloose tufts of said ceramic fibers, depositing said small loose tufts bygravity in a uniform open layer upon said horizontally disposed carrierweb to make a uniform composite of small loose tufts of ceramic fibersand web of carrier fibers, and carding said composite to furtherseparate the ceramic fibers of the small loose tufts and intimatelyblend the ceramic fibers and the carrier fibers of the carded Web.

7. A method of forming an intimate blend of carrier fibers and ceramicfibers including the steps of carding a mass of carrier fibers to form auniform carded web of such fibers, placing said carded web in ahorizontal position, picking a mass of ceramic fibers to form tufts ofceramic fibers, picking said tufts to form smaller tufts, depositingsaid smaller tufts by gravity in a uniform open layer upon said carrierWeb to provide a uniform composite of tufts of ceramic fibers and web ofcarrier fibers, and carding said composite to further separate theceramic fibers of the tufts and intimately blend the ceramic fibers andthe carrier fibers of the carded Web.

8. Apparatus for forming an intimate blend of carrier fibers and ceramicfibers comprising, a first carding means for carding a mass of carrierfibers to produce a carded web, a horizontally disposed conveyoradjacent said first carding means and adapted to receive a carded webtherefrom, a picker for opening a mass of ceramic fibers to provide aplurality of'small tufts of ceramic fibers, said picker being arrangedto deliver said tufts by gravity upon said horizontal conveyor so thatthe tufts are distributed in a uniform open layer upon said web, andsecond carding means in receiving relationship to said conveyor forcarding said web of carrier fibers and said tufts of ceramic fibersdistributed on said web.

References Cited in the file of this patent UNITED STATES PATENTS1,015,764 Potter Jan. 23, 1912 1,179,458 Ryan Apr. 18, 1916 1,235,327Kinsley July 31, 1917 2,665,453 Senior et ai. Jan. 12, 1954 2,682,085Novotny et a1 June 29, 1954 2,816,327 Hunter et al Dec. 17, 1957

1. A METHOD OF FORMING AN INTIMATE BLEND OF CARRIER FIBERS AND OFCERAMIC FIBERS FROM CARRIER FIBERS AND FROM CERAMIC FIBROUS MATERIALTHAT CONTAINS A SUBSTANTIAL PROPORTION OF SHOT THAT MUST BE SEPARATED TOOBTAIN SUBSTANTIALLY SHOT-FREE FIBERS TO PERMIT PROCESSING OF THECERAMIC FIBERS, COMPRISING CARDING SAID CARRIER FIBERS TO FORM A CARDEDWEB OF CARRIER FIBERS, PICKING A MASS OF SAID CERAMIS FIBROUS MATERIALTO SEPARATE THE SHOT AND FIBERS AND TO FORM TUFTS OF CERAMIC FIBERS,PICKING SAID TUFTS OF CERAMIC FIBERS TO FORM SMALLER TUFTS OF CERAMICFIBERS, DEPOSITING